meson format meson.build in subdir should follow meson.format in toplevel directory.

[wrvsrx]

Describe the bug

meson format meson.build in subdir doesn't follow meson.format in toplevel directory.

To Reproduce

|- meson.build
|- meson.format
|- src
|-- meson.build

meson format in src wouldn't follow meson.format if we run meson format in src.

Expected behavior

meson format meson.build in subdir should follow meson.format in toplevel directory.

Maybe we can detect "meson.format" in following manner:

1. Look for a file named meson.format in the directory of the file needing to be formatted and in every parent directory, until we meet a root meson.build (For example, a meson.build contains project(xxx)). So that the formatting behavior is unrelated to the working directory of meson format.
2. A much simplier option is just searching each parent directories for meson.format one by one.

system parameters

• Is this a cross build or just a plain native build (for the same computer)?

  No.

• what operating system (e.g. MacOS Catalina, Windows 10, CentOS 8.0, Ubuntu 18.04, etc.)

  NixOS 25.05

• what Python version are you using e.g. 3.8.0

  3.12

• what meson --version

  1.6.0

• what ninja --version if it's a Ninja build

  It doesn't matter.